Project Abstract Black/African American's (BAAs) are more likely to report insufficient sleep duration (<7 hours) and other sleep deficiencies (e.g., poor sleep quality), and to have advanced Chronic Obstructive Pulmonary Disease (COPD), than Non-Hispanic Whites (NHW) with similar smoking behaviors. Insufficient sleep has been related to: (1) continued cigarette smoking, and (2) impaired lung function in healthy adults. Thus, sleep deficiencies could be an ?upstream? primary and/or secondary prevention target to address racial disparities in tobacco use and COPD onset and progression. Not known are the multi-level (i.e., individual, social and environmental) factors that predict insufficient sleep duration and other sleep deficiencies in BAA's across time, and the extent to which sleep deficiencies predict poorer health outcomes such as continued tobacco use and worsening lung function in BAA smokers. To address these knowledge gaps, we will conduct a multi-disciplinary 5-year prospective observational study that will enroll and follow a representative sample of 480 BAAs who are current smokers, are aged >39 years, and who have prodromal (GOLD stage 0) or early stage COPD (GOLD stage 1-2). We will prospectively examine key individual, social, and environmental variables in concert with objectively measured sleep metrics, tobacco use, inflammatory markers, and lung function in this health disparate sample. Longitudinal mixed, classification and regression, and structural equation modeling will define key predictors (and future intervention targets) of sleep deficiencies in BAA's as well as delineate the extent to which insufficient sleep (and other sleep deficiencies) interact with tobacco use and inflammation markers to predict worsening lung function. The expected outcome from this work is to define multi-level phenotypes of risk for sleep deficiencies, continued tobacco use, and worsening lung function in this health disparate population of mid-life BAA smokers. This work directly aligns with, and advances the NIMHD mission to conduct and support research in minority health and health disparities.